Max Seating Depth Variations in barrels

[alwie]

I have two barrels made by different manufacturers. For the same bullet the seating depth seems to vary btw .050” to 0.100”, depending on the bullet. Is it normal to have that much variation? Seems like a lot to me.

[grayfox]

Which barrels are we talking about?
I have/had 4 barrels from different mfrs:
monster, faxon, uintah, ballistic adv, and the most variation for a given bullet has been 0.010-0.020 in chamber size to lands, and that much only on 1 or 2 bullets. Only a sample of four barrels, though.

[r.tenorio671]

....variance is almost a given, especially if purchasing an "off the shelf" barrel. Factors range from what number in sequence a tube was made with that reamer to how the operator of the machine was feeling that day. This is why one should measure a barrel before installing it. If it is beyond their expectation a return for refund or replacement is made easier. It's also a good idea to hold off making a bulk buy of a specific bullet until the barrel can be measured with that bullet (or bullets). Of course, with handloading, one can always "make do" with what one has on hand to develop a fully functional load, even if it isn't the fastest, longest reaching, most bug-hole producing load.

...current world-events may negatively impact currently weak supplies...

[alwie]

Which barrels are we talking about?
I have/had 4 barrels from different mfrs:
monster, faxon, uintah, ballistic adv, and the most variation for a given bullet has been 0.010-0.020 in chamber size to lands, and that much only on 1 or 2 bullets.  Only a sample of four barrels, though.

I have 2 Shaw Custom barrels and one McGowen Precision barrel.  The McGowen barrel seems to have a much shorter seating depth. The two Shaw barrels are exactly the same. I am using a Hornady seating depth gauge.

[Dino11]

Different bullet profiles will give you different measurements like you are seeing. But if you use the same bullet in two different barrels you will not see as much variance as what you are seeing, unless something is drastically wrong.

[grayfox]

So it's the one barrel from Mcgowen, I would call them to discuss, see what they have to say.

[popgun]

Like has been said, a SAAMI spec. chambered barrel shouldn't have much more than 0.010" variation especially in an AR platform. A custom chambered bolt gun using AI style mags built to optimize a specific bullet is a different story.